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mirror of https://github.com/hsoft/collapseos.git synced 2024-11-27 15:18:05 +11:00

sms/kbd: update instructions for Forth Collapse OS

The keyboard is a bit glitchy, but these are the same glitch as those
that were already present in Z80 Collapse OS. They still need fixing...
This commit is contained in:
Virgil Dupras 2020-05-21 13:57:34 -04:00
parent b06cf09754
commit b5683f447b
11 changed files with 8 additions and 832 deletions

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@ -18,7 +18,6 @@ This recipe is for installing a minimal Collapse OS system on the SMS. There
are other recipes related to the SMS: are other recipes related to the SMS:
* [Interfacing a PS/2 keyboard](kbd/README.md) * [Interfacing a PS/2 keyboard](kbd/README.md)
* [zasm and ed from ROM](romasm/README.md)
## Gathering parts ## Gathering parts

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@ -1,69 +0,0 @@
; 8K of onboard RAM
.equ RAMSTART 0xc000
; Memory register at the end of RAM. Must not overwrite
.equ RAMEND 0xfdd0
jp init
.fill 0x66-$
retn
.inc "err.h"
.inc "ascii.h"
.inc "core.asm"
.inc "str.asm"
.equ PAD_RAMSTART RAMSTART
.inc "sms/pad.asm"
.inc "sms/vdp.asm"
.equ GRID_RAMSTART PAD_RAMEND
.equ GRID_COLS VDP_COLS
.equ GRID_ROWS VDP_ROWS
.equ GRID_SETCELL vdpSetCell
.equ GRID_GETC padGetC
.inc "grid.asm"
.equ STDIO_RAMSTART GRID_RAMEND
.equ STDIO_GETC gridGetC
.equ STDIO_PUTC gridPutC
.inc "stdio.asm"
; *** BASIC ***
; RAM space used in different routines for short term processing.
.equ SCRATCHPAD_SIZE STDIO_BUFSIZE
.equ SCRATCHPAD STDIO_RAMEND
.inc "lib/util.asm"
.inc "lib/ari.asm"
.inc "lib/parse.asm"
.inc "lib/fmt.asm"
.equ EXPR_PARSE parseLiteralOrVar
.inc "lib/expr.asm"
.inc "basic/util.asm"
.inc "basic/parse.asm"
.inc "basic/tok.asm"
.equ VAR_RAMSTART SCRATCHPAD+SCRATCHPAD_SIZE
.inc "basic/var.asm"
.equ BUF_RAMSTART VAR_RAMEND
.inc "basic/buf.asm"
.equ BAS_RAMSTART BUF_RAMEND
.inc "basic/main.asm"
init:
di
im 1
ld sp, RAMEND
call gridInit
call padInit
call vdpInit
call basInit
jp basStart
FNT_DATA:
.bin "fnt/7x7.bin"
.fill 0x7ff0-$
.db "TMR SEGA", 0x00, 0x00, 0xfb, 0x68, 0x00, 0x00, 0x00, 0x4c

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@ -1,22 +0,0 @@
PROGNAME = ps2ctl
AVRDUDEMCU ?= t45
AVRDUDEARGS ?= -c usbtiny -P usb
TARGETS = $(PROGNAME).bin
BASEDIR = ../../..
EDIR = $(BASEDIR)/emul
# Rules
.PHONY: send all clean
all: $(TARGETS)
@echo Done!
send: $(PROGNAME).bin
avrdude $(AVRDUDEARGS) -p $(AVRDUDEMCU) -U flash:w:$(PROGNAME).bin
$(PROGNAME).bin: $(PROGNAME).fs
cd $(EDIR) && ./avra.sh < ../recipes/sms/kbd/$(PROGNAME).fs > ../recipes/sms/kbd/$@
clean:
rm -f $(TARGETS)

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@ -100,16 +100,16 @@ The code expects a SR-latch that works like a 4043, that is, S and R are
triggered high, S makes Q high, R makes Q low. R is hooked to PB4. S is hooked triggered high, S makes Q high, R makes Q low. R is hooked to PB4. S is hooked
to TH (and also the A/B on the '157). Q is hooked to PB0 and TL. to TH (and also the A/B on the '157). Q is hooked to PB0 and TL.
## Usage ## Building the binary
The code in this recipe is set up to listen to the keyboard on port B, leaving We start with the base recipe and add a few things:
port A to drive, for example, an Everdrive with a D-pad. Unlike the generic
SMS recipe, this kernel has no character selection mechanism. It acts like a
regular shell, taking input from the keyboard.
`kernel/sms/kbd.asm` also has a FetchKC implementation for port A if you prefer. 1. at the top: `RAMSTART 0x72 + CONSTANT PS2_MEM`
Just hook it on. I've tried it, it works. 2. After VDP load: `641 LOAD : (ps2kc) (ps2kcB) ;` (that binds us to port B)
3. Right after: `411 414 LOADR` (that gives us `(key)`)
4. After `VDP$`: `PS2$`.
Did you get there? Feels pretty cool huh? Rebuild, send to SMS, then run with your keyboard interface plugged to PortB.
It should mostly work. There are still a few glitches to iron out...
[rc2014-ps2]: ../../rc2014/ps2 [rc2014-ps2]: ../../rc2014/ps2

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@ -1,82 +0,0 @@
; 8K of onboard RAM
.equ RAMSTART 0xc000
; Memory register at the end of RAM. Must not overwrite
.equ RAMEND 0xddd0
jp init
.fill 0x66-$
retn
.inc "err.h"
.inc "ascii.h"
.inc "core.asm"
.inc "str.asm"
.inc "sms/kbd.asm"
.equ KBD_RAMSTART RAMSTART
.equ KBD_FETCHKC smskbdFetchKCB
.inc "kbd.asm"
.inc "sms/vdp.asm"
.equ GRID_RAMSTART KBD_RAMEND
.equ GRID_COLS VDP_COLS
.equ GRID_ROWS VDP_ROWS
.equ GRID_SETCELL vdpSetCell
.equ GRID_GETC kbdGetC
.inc "grid.asm"
.equ STDIO_RAMSTART GRID_RAMEND
.equ STDIO_GETC gridGetC
.equ STDIO_PUTC gridPutC
.inc "stdio.asm"
; *** BASIC ***
; RAM space used in different routines for short term processing.
.equ SCRATCHPAD_SIZE STDIO_BUFSIZE
.equ SCRATCHPAD STDIO_RAMEND
.inc "lib/util.asm"
.inc "lib/ari.asm"
.inc "lib/parse.asm"
.inc "lib/fmt.asm"
.equ EXPR_PARSE parseLiteralOrVar
.inc "lib/expr.asm"
.inc "basic/util.asm"
.inc "basic/parse.asm"
.inc "basic/tok.asm"
.equ VAR_RAMSTART SCRATCHPAD+SCRATCHPAD_SIZE
.inc "basic/var.asm"
.equ BUF_RAMSTART VAR_RAMEND
.inc "basic/buf.asm"
.equ BAS_RAMSTART BUF_RAMEND
.inc "basic/main.asm"
init:
di
im 1
ld sp, RAMEND
; Initialize the keyboard latch by "dummy reading" once. This ensures
; that the adapter knows it can fill its '164.
; Port B TH output, high
ld a, 0b11110111
out (0x3f), a
nop
; Port A/B reset
ld a, 0xff
out (0x3f), a
call kbdInit
call gridInit
call vdpInit
call basInit
jp basStart
FNT_DATA:
.bin "fnt/7x7.bin"
.fill 0x7ff0-$
.db "TMR SEGA", 0x00, 0x00, 0xfb, 0x68, 0x00, 0x00, 0x00, 0x4c

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@ -1,348 +0,0 @@
; Receives keystrokes from PS/2 keyboard and send them to the '164. On the PS/2
; side, it works the same way as the controller in the rc2014/ps2 recipe.
; However, in this case, what we have on the other side isn't a z80 bus, it's
; the one of the two controller ports of the SMS through a DB9 connector.
; The PS/2 related code is copied from rc2014/ps2 without much change. The only
; differences are that it pushes its data to a '164 instead of a '595 and that
; it synchronizes with the SMS with a SR latch, so we don't need PCINT. We can
; also afford to run at 1MHz instead of 8.
; *** Register Usage ***
;
; GPIOR0 flags:
; 0 - when set, indicates that the DATA pin was high when we received a
; bit through INT0. When we receive a bit, we set flag T to indicate
; it.
;
; R16: tmp stuff
; R17: recv buffer. Whenever we receive a bit, we push it in there.
; R18: recv step:
; - 0: idle
; - 1: receiving data
; - 2: awaiting parity bit
; - 3: awaiting stop bit
; R19: Register used for parity computations and tmp value in some other places
; R20: data being sent to the '164
; Y: pointer to the memory location where the next scan code from ps/2 will be
; written.
; Z: pointer to the next scan code to push to the 595
;
.inc "avr.h"
.inc "tn254585.h"
.inc "tn45.h"
; *** Constants ***
.equ CLK 2 ; Port B
.equ DATA 1 ; Port B
.equ CP 3 ; Port B
; SR-Latch's Q pin
.equ LQ 0 ; Port B
; SR-Latch's R pin
.equ LR 4 ; Port B
; init value for TCNT0 so that overflow occurs in 100us
.equ TIMER_INITVAL 0x100-100
; *** Code ***
rjmp main
rjmp hdlINT0
; Read DATA and set GPIOR0/0 if high. Then, set flag T.
; no SREG fiddling because no SREG-modifying instruction
hdlINT0:
sbic PINB, DATA ; DATA clear? skip next
sbi GPIOR0, 0
set
reti
main:
ldi r16, RAMEND&0xff
out SPL, r16
ldi r16, RAMEND}8
out SPH, r16
; init variables
clr r18
out GPIOR0, r18
; Setup int0
; INT0, falling edge
ldi r16, 0x02 ; ISC01
out MCUCR, r16
; Enable INT0
ldi r16, 0x40 ; INT0
out GIMSK, r16
; Setup buffer
clr YH
ldi YL, SRAM_START&0xff
clr ZH
ldi ZL, SRAM_START&0xff
; Setup timer. We use the timer to clear up "processbit" registers after
; 100us without a clock. This allows us to start the next frame in a
; fresh state. at 1MHZ, no prescaling is necessary. Each TCNT0 tick is
; already 1us long.
ldi r16, 0x01 ; CS00 - no prescaler
out TCCR0B, r16
; init DDRB
sbi DDRB, CP
cbi PORTB, LR
sbi DDRB, LR
sei
loop:
brts processbit ; flag T set? we have a bit to process
cp YL, ZL ; if YL == ZL, buffer is empty
brne sendTo164 ; YL != ZL? our buffer has data
; nothing to do. Before looping, let's check if our communication timer
; overflowed.
in r16, TIFR
sbrc r16, 1 ; TOV0
rjmp processbitReset ; Timer0 overflow? reset processbit
; Nothing to do for real.
rjmp loop
; Process the data bit received in INT0 handler.
processbit:
in r19, GPIOR0 ; backup GPIOR0 before we reset T
andi r19, 0x1 ; only keep the first flag
cbi GPIOR0, 0
clt ; ready to receive another bit
; We've received a bit. reset timer
rcall resetTimer
; Which step are we at?
tst r18
breq processbits0
cpi r18, 1
breq processbits1
cpi r18, 2
breq processbits2
; step 3: stop bit
clr r18 ; happens in all cases
; DATA has to be set
tst r19 ; Was DATA set?
breq loop ; not set? error, don't push to buffer
; push r17 to the buffer
st Y+, r17
rcall checkBoundsY
rjmp loop
processbits0:
; step 0 - start bit
; DATA has to be cleared
tst r19 ; Was DATA set?
brne loop ; Set? error. no need to do anything. keep r18
; as-is.
; DATA is cleared. prepare r17 and r18 for step 1
inc r18
ldi r17, 0x80
rjmp loop
processbits1:
; step 1 - receive bit
; We're about to rotate the carry flag into r17. Let's set it first
; depending on whether DATA is set.
clc
sbrc r19, 0 ; skip if DATA cleared.
sec
; Carry flag is set
ror r17
; Good. now, are we finished rotating? If carry flag is set, it means
; that we've rotated in 8 bits.
brcc loop ; we haven't finished yet
; We're finished, go to step 2
inc r18
rjmp loop
processbits2:
; step 2 - parity bit
mov r1, r19
mov r19, r17
rcall checkParity ; --> r16
cp r1, r16
brne processbitError ; r1 != r16? wrong parity
inc r18
rjmp loop
processbitError:
clr r18
ldi r19, 0xfe
rcall sendToPS2
rjmp loop
processbitReset:
clr r18
rcall resetTimer
rjmp loop
; Send the value of r20 to the '164
sendTo164:
sbis PINB, LQ ; LQ is set? we can send the next byte
rjmp loop ; Even if we have something in the buffer, we
; can't: the SMS hasn't read our previous
; buffer yet.
; We disable any interrupt handling during this routine. Whatever it
; is, it has no meaning to us at this point in time and processing it
; might mess things up.
cli
sbi DDRB, DATA
ld r20, Z+
rcall checkBoundsZ
ldi r16, 8
sendTo164Loop:
cbi PORTB, DATA
sbrc r20, 7 ; if leftmost bit isn't cleared, set DATA high
sbi PORTB, DATA
; toggle CP
cbi PORTB, CP
lsl r20
sbi PORTB, CP
dec r16
brne sendTo164Loop ; not zero yet? loop
; release PS/2
cbi DDRB, DATA
sei
; Reset the latch to indicate that the next number is ready
sbi PORTB, LR
cbi PORTB, LR
rjmp loop
resetTimer:
ldi r16, TIMER_INITVAL
out TCNT0, r16
ldi r16, 0x02 ; TOV0
out TIFR, r16
ret
; Send the value of r19 to the PS/2 keyboard
sendToPS2:
cli
; First, indicate our request to send by holding both Clock low for
; 100us, then pull Data low
; lines low for 100us.
cbi PORTB, CLK
sbi DDRB, CLK
rcall resetTimer
; Wait until the timer overflows
in r16, TIFR
sbrs r16, 1 ; TOV0
rjmp $-4
; Good, 100us passed.
; Pull Data low, that's our start bit.
cbi PORTB, DATA
sbi DDRB, DATA
; Now, let's release the clock. At the next raising edge, we'll be
; expected to have set up our first bit (LSB). We set up when CLK is
; low.
cbi DDRB, CLK ; Should be starting high now.
; We will do the next loop 8 times
ldi r16, 8
; Let's remember initial r19 for parity
mov r1, r19
sendToPS2Loop:
; Wait for CLK to go low
sbic PINB, CLK
rjmp $-2
; set up DATA
cbi PORTB, DATA
sbrc r19, 0 ; skip if LSB is clear
sbi PORTB, DATA
lsr r19
; Wait for CLK to go high
sbis PINB, CLK
rjmp $-2
dec r16
brne sendToPS2Loop ; not zero? loop
; Data was sent, CLK is high. Let's send parity
mov r19, r1 ; recall saved value
rcall checkParity ; --> r16
; Wait for CLK to go low
sbic PINB, CLK
rjmp $-2
; set parity bit
cbi PORTB, DATA
sbrc r16, 0 ; parity bit in r16
sbi PORTB, DATA
; Wait for CLK to go high
sbis PINB, CLK
rjmp $-2
; Wait for CLK to go low
sbic PINB, CLK
rjmp $-2
; We can now release the DATA line
cbi DDRB, DATA
; Wait for DATA to go low. That's our ACK
sbic PINB, DATA
rjmp $-2
; Wait for CLK to go low
sbic PINB, CLK
rjmp $-2
; We're finished! Enable INT0, reset timer, everything back to normal!
rcall resetTimer
clt ; also, make sure T isn't mistakely set.
sei
ret
; Check that Y is within bounds, reset to SRAM_START if not.
checkBoundsY:
tst YL
breq $+4
ret ; not zero, nothing to do
; YL is zero. Reset Y
clr YH
ldi YL, SRAM_START&0xff
ret
; Check that Z is within bounds, reset to SRAM_START if not.
checkBoundsZ:
tst ZL
breq $+4
ret ; not zero, nothing to do
; ZL is zero. Reset Z
clr ZH
ldi ZL, SRAM_START&0xff
ret
; Counts the number of 1s in r19 and set r16 to 1 if there's an even number of
; 1s, 0 if they're odd.
checkParity:
ldi r16, 1
lsr r19
brcc $+4 ; Carry unset? skip next
inc r16 ; Carry set? We had a 1
tst r19 ; is r19 zero yet?
brne checkParity+2 ; no? loop and skip first LDI
andi r16, 0x1 ; Sets Z accordingly
ret

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@ -1 +0,0 @@
user.h

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@ -1,21 +0,0 @@
BASEDIR = ../../..
ZASM = $(BASEDIR)/emul/zasm/zasm
KERNEL = $(BASEDIR)/kernel
APPS = $(BASEDIR)/apps
.PHONY: all clean
all: os.sms
# -o value synced with offset in glue.asm
ed.bin: $(APPS)/ed/glue.asm
$(ZASM) -o 1f $(KERNEL) $(APPS) user.h < $(APPS)/ed/glue.asm > $@
# -o value synced with offset in glue.asm
zasm.bin: $(APPS)/zasm/glue.asm
$(ZASM) -o 24 $(KERNEL) $(APPS) user.h < $(APPS)/zasm/glue.asm > $@
os.sms: glue.asm ed.bin zasm.bin
$(ZASM) $(KERNEL) $(APPS) ed.bin zasm.bin < glue.asm > $@
clean:
rm -f os.sms ed.bin zasm.bin

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@ -1,61 +0,0 @@
# zasm and ed from ROM
SMS' RAM is much tighter than in the RC2014, which makes the idea of loading
apps like zasm and ed in memory before using it a bit wasteful. In this recipe,
we'll include zasm and ed code directly in the kernel and expose them as shell
commands.
Moreover, we'll carve ourselves a little 1K memory map to put a filesystem in
there. This will give us a nice little system that can edit small source files
compile them and run them.
## Gathering parts
* A SMS that can run Collapse OS.
* A [PS/2 keyboard adapter](../kbd/README.md)
## Build
There's nothing special with building this recipe. Like the base recipe, run
`make` then copy `os.sms` to your destination medium.
If you look at the makefile, however, you'll see that we use a new trick here:
we embed "apps" binaries directly in our ROM so that we don't have to load them
in memory.
## Usage
Alright, here's what we'll do: we'll author a source file, assemble it and run
it, *all* on your SMS! Commands:
Collapse OS
> fnew 1 src
> ed src
: 1i
.org 0xc200
: 1a
ld hl, sFoo
: 2a
call 0x3f
: 3a
xor a
: 4a
ret
: 5a
sFoo: .db "foo", 0
: w
> fnew 1 dest
> fopn 0 src
> fopn 1 dest
> zasm 1 2
First pass
Second pass
> dest
foo>
Awesome right? Some precisions:
* Our glue code specifies a `USER_RAMSTART` of `0xc200`. This is where
`dest` is loaded by the `pgm` shell hook.
* `0x3f` is the offset of `printstr` in the jump table of our glue code.
* `xor a` is for the command to report as successful to the shell.

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@ -1,187 +0,0 @@
; TODO: This recipe has not been tested since its conversion to the BASIC shell.
; My PS/2 adapter has been acting up and probably has a loose wire. I need to
; fix it beore I can test this recipe on real hardware.
; But theoretically, it works...
; 8K of onboard RAM
.equ RAMSTART 0xc000
.equ USER_CODE 0xd500
; Memory register at the end of RAM. Must not overwrite
.equ RAMEND 0xddd0
jp init
; *** JUMP TABLE ***
jp strncmp
jp upcase
jp findchar
jp parseHex
jp blkSel
jp blkSet
jp fsFindFN
jp fsOpen
jp fsGetB
jp fsPutB
jp fsSetSize
jp printstr
jp _blkGetB
jp _blkPutB
jp _blkSeek
jp _blkTell
jp printcrlf
jp stdioPutC
jp stdioReadLine
.fill 0x66-$
retn
.inc "err.h"
.inc "ascii.h"
.inc "blkdev.h"
.inc "fs.h"
.inc "core.asm"
.inc "str.asm"
.inc "sms/kbd.asm"
.equ KBD_RAMSTART RAMSTART
.equ KBD_FETCHKC smskbdFetchKCB
.inc "kbd.asm"
.inc "sms/vdp.asm"
.equ GRID_RAMSTART KBD_RAMEND
.equ GRID_COLS VDP_COLS
.equ GRID_ROWS VDP_ROWS
.equ GRID_SETCELL vdpSetCell
.equ GRID_GETC kbdGetC
.inc "grid.asm"
.equ STDIO_RAMSTART GRID_RAMEND
.equ STDIO_GETC gridGetC
.equ STDIO_PUTC gridPutC
.inc "stdio.asm"
.equ MMAP_START 0xd700
; 0x180 is to leave some space for the stack
.equ MMAP_LEN RAMEND-MMAP_START-0x180
.inc "mmap.asm"
.equ BLOCKDEV_RAMSTART STDIO_RAMEND
.equ BLOCKDEV_COUNT 3
.inc "blockdev.asm"
; List of devices
.dw mmapGetB, mmapPutB
.dw f0GetB, f0PutB
.dw f1GetB, f1PutB
.equ FS_RAMSTART BLOCKDEV_RAMEND
.equ FS_HANDLE_COUNT 2
.inc "fs.asm"
; *** BASIC ***
; RAM space used in different routines for short term processing.
.equ SCRATCHPAD_SIZE STDIO_BUFSIZE
.equ SCRATCHPAD FS_RAMEND
.inc "lib/util.asm"
.inc "lib/ari.asm"
.inc "lib/parse.asm"
.inc "lib/fmt.asm"
.equ EXPR_PARSE parseLiteralOrVar
.inc "lib/expr.asm"
.inc "basic/util.asm"
.inc "basic/parse.asm"
.inc "basic/tok.asm"
.equ VAR_RAMSTART SCRATCHPAD+SCRATCHPAD_SIZE
.inc "basic/var.asm"
.equ BUF_RAMSTART VAR_RAMEND
.inc "basic/buf.asm"
.equ BFS_RAMSTART BUF_RAMEND
.inc "basic/fs.asm"
.inc "basic/blk.asm"
.equ BAS_RAMSTART BFS_RAMEND
.inc "basic/main.asm"
; USER_CODE is set according to this output below.
.out BAS_RAMEND
init:
di
im 1
ld sp, RAMEND
; init a FS in mmap
ld hl, MMAP_START
ld a, 'C'
ld (hl), a
inc hl
ld a, 'F'
ld (hl), a
inc hl
ld a, 'S'
ld (hl), a
call fsInit
xor a
ld de, BLOCKDEV_SEL
call blkSel
call fsOn
call kbdInit
call gridInit
call vdpInit
call basInit
ld hl, basFindCmdExtra
ld (BAS_FINDHOOK), hl
jp basStart
basFindCmdExtra:
ld hl, basFSCmds
call basFindCmd
ret z
ld hl, basBLKCmds
call basFindCmd
ret z
ld hl, .mycmds
call basFindCmd
ret z
jp basPgmHook
.mycmds:
.db "ed", 0
.dw 0x1f00
.db "zasm", 0
.dw 0x2400
.db 0xff
f0GetB:
ld ix, FS_HANDLES
jp fsGetB
f0PutB:
ld ix, FS_HANDLES
jp fsPutB
f1GetB:
ld ix, FS_HANDLES+FS_HANDLE_SIZE
jp fsGetB
f1PutB:
ld ix, FS_HANDLES+FS_HANDLE_SIZE
jp fsPutB
; last time I checked, PC at this point was 0x128f. Let's give us a nice margin
; for the start of ed.
.fill 0x1f00-$
.bin "ed.bin"
; Last check: 0x23b0
.fill 0x2400-$
.bin "zasm.bin"
FNT_DATA:
.bin "fnt/7x7.bin"
.fill 0x7ff0-$
.db "TMR SEGA", 0x00, 0x00, 0xfb, 0x68, 0x00, 0x00, 0x00, 0x4c

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@ -1,32 +0,0 @@
.equ USER_CODE 0xc200
; Make ed fit in SMS's memory
.equ ED_BUF_MAXLINES 0x100
.equ ED_BUF_PADMAXLEN 0x800
; Make zasm fit in SMS's memory
.equ ZASM_REG_MAXCNT 0x80
.equ ZASM_LREG_MAXCNT 0x10
.equ ZASM_REG_BUFSZ 0x800
.equ ZASM_LREG_BUFSZ 0x100
; *** JUMP TABLE ***
.equ strncmp 0x03
.equ upcase @+3
.equ findchar @+3
.equ parseHex @+3
.equ blkSel @+3
.equ blkSet @+3
.equ fsFindFN @+3
.equ fsOpen @+3
.equ fsGetB @+3
.equ fsPutB @+3
.equ fsSetSize @+3
.equ printstr @+3
.equ _blkGetB @+3
.equ _blkPutB @+3
.equ _blkSeek @+3
.equ _blkTell @+3
.equ printcrlf @+3
.equ stdioPutC @+3
.equ stdioReadLine @+3